KR101274546B1 - Supply apparatus for liquefied gas fuel - Google Patents

Abstract

A liquefied gas fuel supplying device which supplies liquefied gas fuel to a fuel injection valve in a liquid state and supplies it to an engine, greatly reduces noise due to fuel pump operation while ensuring ease of maintenance of the fuel pump.

Liquefied gas fuel installed in the fuel supply system of an engine by sending the liquefied gas fuel stored in the fuel tank 10A to the fuel injection valve in a liquid state by the fuel pump 11A and returning the surplus fuel to the fuel tank 10A. In the supply device 1A, the fuel pump 11A is disposed outside the fuel tank 10A for external attachment, and most of the fuel pump 11A outside the fuel pump 11A except for a portion near the fuel tank 10A. It is assumed that the soundproof case 20 is installed to cover the housing.

Description

Liquefied Gas Fuel Supply Unit {SUPPLY APPARATUS FOR LIQUEFIED GAS FUEL}

1 is a layout view of a fuel supply system provided with a liquefied gas fuel supply device according to an embodiment of the present invention.

FIG. 2 is an enlarged partial view showing the details of a liquefied gas fuel supply device in the liquefied gas fuel supply device of FIG. 1. FIG.

3 is a longitudinal sectional view showing details of a vehicle installation state of a fuel pump in the liquefied gas fuel supply device of FIG. 2;

4 is a longitudinal sectional view showing details of a vehicle installation state of another type of fuel pump in the liquefied gas fuel supply device of FIG. 2;

5 is a layout view showing a conventional example.

(Explanation of Symbols)

1A: liquefied gas fuel supply device

8: Fuel injection valve

9A: Fuel supply piping

9B fuel return piping

10A: Fuel Tank

10a: fuel outlet valve

11A: Fuel Pump

11a: fuel intake

11b: Booster

11c: vapor separator

15, 21: soundproofing

20: soundproof case

22: soundproof case

22a: Soundproof case on fuel pump side

22b: Fuel tank side soundproofing case

22c: connector

The present invention relates to a liquefied gas fuel supply device installed in an engine fuel supply system, and in particular, a liquefied gas that is supplied to a fuel injection valve in a liquid state to be supplied to a fuel injection valve in a liquid state, which is easier to vaporize compared to gasoline such as LPG or DME. It relates to a fuel supply device.

A liquefied gas fuel supply device for pumping relatively liquefied liquefied gas fuel, such as LPG or DME, charged in a fuel tank by a fuel pump and injecting the liquid from a fuel injection valve to an intake pipe of an engine in a liquid state, for example, is a Japanese patent. It is known from the prior art as described in the publication 2003-120443.

Fig. 5 shows a fuel supply system of an engine provided with the conventional liquefied gas fuel supply device, and the liquefied gas fuel supply device 1B needs to reliably remove the liquid fuel filled in the fuel tank 10B to the end. For this reason, the fuel pump 11B employs a submerged fuel pump provided on the bottom side of the fuel tank 10B. The fuel stored in the fuel tank 10B is pressurized by the fuel pump 11B and sent to the fuel injection valve 8 provided on the engine 50 side in a liquid state through the fuel supply pipe 9A. The surplus fuel not injected by the injection valve 8 is returned to the fuel tank 10B through the fuel return pipe 9B.

The fuel tank 10B for filling liquefied gas fuel, such as liquid LPG, has a cylindrical shape having both ends of a steel sphere having a hemispherical surface made of steel from the necessity of storing liquid high pressure liquefied gas fuel at normal temperature. Therefore, the operation sound of the fuel pump 11B accommodated at the time of pump operation is reflected by the fuel tank 10B, and it is easy to generate a noise, and it is often unpleasant to a driver and an occupant.

In addition, since the fuel pump 11B is accommodated in the fuel tank 10B for sealing and storing the liquefied gas fuel as described above, when the state of the fuel pump 11B is not good or malfunctions, the fuel tank 10B Since it is necessary to open and separate the fuel tank 10B after transferring the internal liquefied gas fuel to another container or consuming it to the end, it is very difficult to maintain the fuel pump 11B.

Therefore, in addition to providing a fuel pump in the vicinity of the fuel tank to accommodate the fuel pump therein, the fuel pump is accommodated in the fuel tank in addition to the reduction in the amount or consumption of fuel during maintenance, thereby facilitating maintenance work. It is proposed to reduce the echo caused by the pump operation as compared to the above.

However, in this case, a fuel take-off valve and an eddy current prevention valve (EFV) with a relatively narrow passage diameter are provided between the fuel tank and the fuel pump because it is necessary to comply with the LP gas vehicle handling standards, and the fuel passes through the fuel pump. Although a vapor lock may occur and fuel may not be delivered reliably, reverberation by pump operation may be reduced, placing the fuel pump outside the fuel tank may cause the pump operation sound to In some cases, the vehicle can be heard directly up to the living space of the vehicle, and thus there is a problem that it is not perfect as a noise countermeasure.

The present invention is intended to solve the above problems, and the liquefied gas fuel supply apparatus for supplying liquefied gas fuel to the fuel injection valve in a liquid state and supplying it to the engine, easy maintenance without increasing the manufacturing cost The problem is to reduce noise caused by the operation of the fuel pump while ensuring the safety of fuelization and fuel supply.

In order to solve the above problems, the present invention provides a liquefied gas fuel stored in a fuel tank to a fuel injection valve of an engine in a liquid state by a fuel pump, and returns the surplus fuel to the fuel tank. In the apparatus, the fuel pump is disposed outside the fuel tank, and has a fuel discharge valve and a vortex prevention valve in a fuel passage connecting the fuel tank and the fuel pump, and further downstream of the fuel pump. And a fuel shutoff valve.

In this way, the fuel pump is installed on the outside of the fuel tank in a simple configuration so as to reduce the noise generated by the operation of the fuel pump without increasing the manufacturing cost, thereby making the noise less, and extracting the fuel between the fuel tank and the fuel pump. By installing the valve and the vortex prevention valve, maintenance of the fuel pump can be made easy while observing the safety standards of the apparatus, and stable fuel supply can be easily realized.

In addition, in the case where a plurality of fuel passages connecting the fuel tank and the fuel pump are provided in parallel with the fuel ejection valve and the vortex prevention valve, in order to prevent vapor lock of the fuel pump, a larger diameter than the usual fuel ejection is performed. Since the valve and the vortex prevention valve are unnecessary, the versatility is high, and a low cost and more stable fuel supply can be performed.

In addition, the present invention is the fuel pump is disposed outside the fuel tank, the fuel inlet for introducing the liquefied gas fuel inside and retained once, the boosting portion for pressurizing the introduced fuel, vapor contained in the pressurized fuel A vapor separation section for separating the fuel cell; and a fuel supply path extending from the fuel tank to the fuel intake unit; and the fuel return path extending from the vapor separation unit to the fuel tank. It is characterized by being.

The simple configuration of simply installing the fuel pump outside the fuel tank reduces the noise caused by the operation of the fuel pump without increasing the cost, and thus makes the noise less and maintains the fuel pump easier. The vapor separation section is provided so that the separated vapor is returned to the fuel tank by the fuel return path, and the vapor is contained in the discharged fuel or the vapor accumulation in the fuel pump is effectively avoided to prevent trouble such as vapor lock. Stable fuel supply can be achieved.

The fuel pump is made into a horizontal cylindrical shape, and the boosting part is made into a horizontal cylindrical shape, and the vapor separation part is composed of a substantially annular space formed along the outer periphery of the boosting part, and the vapor generated in the boosting part is introduced. If the fuel return path is extended from the discharge hole formed in the uppermost part, the fuel pump is substantially accommodated in an empty space formed below the cylindrical fuel tank horizontally having both ends as a spherical shape when the vehicle is mounted. In addition, the wafer can be efficiently removed.

In the above-described liquefied gas fuel supply apparatus, a vapor return path for transporting excess fuel not injected by the fuel injection valve to the vapor separation unit is connected, and the vapor in the return fuel in addition to the vapor generated in the boosting process. By sending the fuel to the fuel tank together with the return fuel, the vapor to the fuel tank can be smoothly discharged and the vapor in the fuel sent to the engine can be reliably removed, thereby achieving a more stable fuel supply.

The present invention also provides a liquefied gas fuel supply apparatus for an engine, wherein the liquefied gas fuel stored in the fuel tank is sent to the fuel injection valve of the engine in a liquid state by a fuel pump, and the surplus fuel is returned to the fuel tank. The fuel pump is disposed outside the fuel tank, and a soundproof case is provided to cover and accommodate the outside of the fuel pump except for a portion close to the fuel tank.

In this way, the simple configuration of only installing the fuel pump outside the fuel tank can reduce the echo sound caused by the operation of the fuel pump and facilitate the maintenance of the fuel pump. However, by installing a soundproof case covering the outside of the fuel pump, Since the pump operation sound directly heard in the vehicle occupant space with the passenger can be reduced, it is possible to greatly reduce the noise caused by the fuel pump operation. In particular, the soundproof case is configured such that the fuel pump side soundproof case and the fuel tank side soundproof case are connected by a connecting tube having airtightness covering the fuel supply line and the fuel return line. Can provide excellent things.

In the liquefied gas fuel supply device, by providing a soundproof layer made of a sound insulating material or a sound absorbing material on the inner surface side or the outer surface side of the soundproof case, the effect of reducing noise is remarkable, and the fuel pump in the liquefied gas fuel supply device. By providing a sound insulation layer made of a sound insulating material or a sound absorbing material that adheres to the outer surface and covers most of them, the effect of reducing noise is further improved, and the soundproof case is caught by a locking structure provided on the outer surface of the fuel tank, and is detached from the fuel tank. When the installation is possible, the soundproof case is not obstructed in the maintenance of the fuel pump.

According to the present invention, noise due to the operation of the fuel pump can be reduced while facilitating maintenance and securing fuel supply stability without increasing the manufacturing cost.

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings.

Fig. 1 shows a layout view of a fuel supply system of an engine provided with a liquefied gas fuel supply device 1A according to an example of the embodiment of the present invention, wherein the fuel supply pipe 9A extending from the fuel tank 10A is provided. The fuel is distributed from the fuel rail 7 to the fuel injection valve 8 disposed in the intake pipe path of the engine 50 from the fuel rail 7 via the fuel pump 11A. . The fuel return pipe 9B is extended from the fuel rail 7 and the fuel contained in the soundproof case 20 shown by a broken line while the outer surface is covered with the soundproof material 15 via the fuel pump 11A. It is connected to the tank 10A and comprises the return type fuel supply system.

The sound insulating material 15 is formed by adhering a sound absorbing material made of urethane foam or the like so that the inner shape thereof matches the outer shape of the fuel pump 11A so as to be in close contact with the outer surface of the fuel pump 11A, or with a lead sheet or the like. The sound insulating material formed can be attached to the outer surface of the fuel pump. In particular, when the fuel pump 11A is disposed at the front side of the vehicle below the lowest level of the fuel tank 10A, the remaining fuel in the fuel tank 10A can be completely used to the end, and the fuel tank 10A and the rear It can arrange in the space which consists of empty spaces between sheets.

In addition, two shut-off valves 5a and 5b are provided in the fuel supply pipe 9A located downstream of the fuel pump 11A to ensure the safety of the device. The fuel return pipe 9B has a pressure regulator. (3) is provided so that the pressure of the return fuel returned to the fuel tank 10A is adjusted to be substantially the same as a conventional liquefied gas fuel supply apparatus of the related art. In addition, in this embodiment, the case where LPG is used as fuel is demonstrated.

Fig. 2 shows an enlarged partial view of the liquefied gas fuel supply device 1A, and the liquefied gas fuel supply device 1A includes a fuel tank 10A and a fuel pump 11A disposed outside the fuel tank 10A. A fuel take-off valve 10a serving as a vortex prevention valve is provided in the fuel supply pipe 9A to be connected, and a fuel pump 11A having the fuel take-out valve 10a and a fuel tank 10A are connected. The fuel supply pipe 9A is provided in two systems and is provided in parallel. In addition, the surplus fuel which is not injected by the fuel injection valve 8 is fueled through the fuel return pipe 9B in which the fuel ejection valve 100a which serves as the above-mentioned vortex prevention valve via the fuel pump 11A is arranged. It is supposed to return to the tank 10A.

By the way, when the fuel pump 11A is installed outside the fuel tank 10A, the fuel outlet valve and the vortex in the fuel passage between the fuel tank 10A and the fuel pump 11A in order to comply with the LPG automobile handling structure standard. Since it is necessary to provide a check valve, a fuel take-out valve 10a which also serves as a vortex check valve is provided. In the case of the usual diameter, fuel may pass through the fuel pump 11A due to the passage of fuel. In the embodiment, by providing a plurality of systems (two systems) of fuel passages having a fuel takeoff valve 10a which also serves as a vortex prevention valve, generation of vapor lock can be avoided even when a normal diameter is used.

Thus, by arranging the fuel take-off valves 10a serving as a plurality of vortex check valves having a normal diameter in parallel, the vapor lock can be reliably prevented, and only in this part, the vortex check valves having a relatively large diameter are provided. It is not necessary to prepare a fuel take-off valve 100a which also serves as a gas, thereby ensuring a stable fuel supply with excellent versatility and relatively low cost.

In addition, the fuel return pipe 9B is connected to the fuel tank 10A via the fuel pump 11A, and the fuel ejection valve serving as the above-described vortex preventing valve between the fuel pump 11A and the fuel tank 10A ( By providing 10a), surplus fuel not injected by the fuel injection valve 8 is stably and safely returned to the fuel tank 10A.

Moreover, although the fuel used was LPG in this embodiment, if it is a liquefied gas fuel which is easy to vaporize compared with gasoline at normal temperature, it is the same also when using other fuels, such as DME. In addition, the fuel supply pipe 9A in parallel with the fuel ejection valve 10a, which also serves as a vortex prevention valve connecting the fuel tank 10A and the fuel pump 11A, does not cause a significant increase in manufacturing costs. There is no limit to the number.

In addition, a vapor separation section 11c is formed which comprises a horizontal annular space surrounding the outer circumference of the horizontal cylindrical boosting portion 11b accommodated in the horizontal cylindrical fuel pump 11A. The fuel injection valve 8 The fuel return piping 9B for returning the surplus fuel not injected by the fuel cell to the fuel tank 10 side is connected, and the fuel return path (fuel return piping 9B) is connected from the purge hole 110 at the top of the space. It is extended and connected to the fuel tank 10A. Therefore, the vapor generated in the boosting section 11b is introduced, separated by the specific gravity difference, and returned to the fuel tank.

Further, the booster section 11b is connected to the fuel return line 9B by the vapor separation section 11c, and the return fuel is returned to the fuel tank 10A via the vapor separation section 11c. In addition to separating the generated vapor, the vapor contained in the returned fuel can be separated and collected in one place, and this can be smoothly sent to the fuel tank 10A together with the returned fuel, thereby effectively avoiding various troubles caused by the vapor. can do.

Fig. 3 shows a longitudinal cross-sectional view of a state in which a liquefied gas fuel supply device 1A is installed in a vehicle. The fuel pump 11A is provided outside the fuel tank 10A, and both ends are easily reflected inside. Even when the fuel tank 10A made of steel having a spherical surface is used, the noise caused by the operation of the fuel pump 11A is hardly heard by the driver and passengers. In the maintenance of the fuel pump 11A, the back plate of the rear seat is removed, the cover plate 30 is opened, and each valve is closed to consume the fuel in the fuel pump 11A. It can be carried out. The liquefied gas fuel supply device 1A is provided in the rear space (inside the trunk room) of the rear seat, indicated by broken lines.

In addition, in the case of the external attachment type in which the fuel pump 11A is disposed outside the fuel tank 10A, in general, where the arrangement space is a problem, as shown in FIG. 3, both ends are spherical in this embodiment. Since the empty space formed in the vehicle front side below the cylindrical fuel tank 10A is used, it is not necessary to secure an extra space.

On the other hand, as shown in Fig. 3, the soundproof case 20 is formed of a case-like member having an open upper side, and the open end thereof is cut to match the outer surface shape of the fuel tank 10A, and the fuel pump 11A. By attaching to the fuel tank 10A while accommodating the gas, the interior and the exterior of the fuel pump 11A are isolated to prevent noise from leaking out.

In addition, the opening end of the soundproof case 20 is provided with a locking flange 20a, which is caught by the inside of the locking claw 10b provided at at least two upper and lower positions of the fuel tank 10A circumferential surface. 20 is easily fixed to the fuel tank 10A, and the fuel tank 10A can be easily separated by removing the locking claw 10b.

In addition, the sound insulation material 21 made of the same sound insulation material or sound absorbing material as the above sound insulation material 15 is provided to cover most of the inner surface of the sound insulation case 20 to form a sound insulation layer, and the sound generated from the inside is leaked to the outside. The amount is to be kept to a minimum. In addition, it is needless to say that the sound insulation material 21 can obtain the same effect even if it installs in the outer surface or both inside and outside both in addition to installing it on the inner surface.

In this manner, the fuel pump 11A externally attached to the fuel tank 10A is directly covered with the soundproof material 15, and the outside thereof is covered with the soundproof case 20 having the soundproof material 21. The operation sound of the fuel pump 11A penetrating into the living space of the vehicle can be minimized. Moreover, by making the sound insulation case 20 detachable from the fuel tank 10A, the fall of the maintenance property of 11 A of fuel pumps can be suppressed to the minimum.

FIG. 4 shows an embodiment of another type of sound insulation case 22 having the same sound insulation effect as the sound insulation case 20 shown in FIG. 3, and the sound insulation case 22 is provided with an outer side of the fuel pump 11A. The fuel pump side sound insulation case 22a which covers and accommodates the fuel supply piping 9A connected to and between the fuel tank 10A, and the fuel return piping 9B, and the fuel supply piping of the fuel tank 10A ( 9A) and a fuel tank side soundproof case 22b covering the outer surface for connecting the fuel return pipe 9B except for the fuel supply pipe 9A and the fuel return pipe 9B, and the fuel pump side The sound insulation case 22a and the fuel tank side sound insulation case 22b are connected by the airtight connection pipe 22c which covers the said fuel supply piping 9A and the fuel return piping 9B.

According to the sound insulation case 22 shown in this embodiment, the fuel supply piping 9A connected between the fuel pump 11A, the fuel tank 10A, and fuel similarly to the sound insulation case 20 shown in FIG. Needless to say, the return pipe 9B is integrally covered to exert an excellent soundproofing effect, and the fuel pump side soundproofing case 22a and the fuel tank each having the fuel pump 11A and the fuel tank 10A separately formed. The configuration of the side sound insulation case 22b increases the degree of freedom in the layout of the arrangement, and is also excellent in terms of safety, inspection and maintenance.

As described above, according to the present invention, it is possible to reduce noise due to the operation of the fuel pump while facilitating maintenance and securing fuel supply stability without increasing the manufacturing cost.

Claims (9)

The liquefied gas fuel stored in the fuel tank is sent to the fuel injection valve of the engine in a liquid state by a fuel passage connecting the fuel tank and the fuel pump, and the surplus fuel is returned to the fuel tank by a fuel return pipe provided with a pressure regulator. In the liquefied gas fuel supply apparatus for an engine, the fuel pump and the pressure regulator are disposed outside the fuel tank, and the fuel passage is provided with a fuel ejection valve and a vortex prevention valve. A liquefied gas fuel supply device having a fuel shutoff valve downstream, wherein a plurality of portions connecting the fuel tank and the fuel pump in the fuel passage connecting the fuel tank and the fuel injection valve are arranged in parallel to each other. Liquefied gas fuel supply unit. The liquefied gas fuel supply apparatus according to claim 1, wherein a plurality of fuel passages provided with the fuel ejecting valve and the vortex prevention valve and connecting the fuel tank and the fuel pump are provided in parallel with each other. The fuel pump according to claim 1 or 2, wherein the fuel pump includes: a fuel suction unit for introducing liquefied gas fuel into and holding the liquid gas; a boosting unit for pressurizing the introduced fuel; and a vapor separating the vapor contained in the pressurized fuel. And a fuel supply passage extending from the fuel tank to the fuel intake portion, and wherein the fuel return passage extends from the vapor separation portion and is connected to the fuel tank. Liquefied gas fuel supply unit. The fuel intake part according to claim 1 or 2, wherein the fuel pump is in the shape of a horizontal cylinder and the boosting part is in the shape of a horizontal cylinder. A pressurized boosting unit and a vapor generated in the boosting unit are introduced to separate a vapor contained in the pressurized fuel, and a vapor separating unit including an annular space formed along an outer circumference of the boosting unit. A fuel supply path extending from the fuel tank is connected to the unit, and the fuel return path is extended from the vapor separation unit and connected to the fuel tank. The fuel pump according to claim 1 or 2, wherein the fuel pump is configured to separate a fuel suction part for introducing liquefied gas fuel into and holding the liquid gas, a boosting part for pressurizing the introduced fuel, and a vapor contained in the pressurized fuel. And a vapor separation section connected to a fuel return path for conveying surplus fuel not injected by the fuel injection valve. The liquefied gas fuel supply apparatus according to claim 1 or 2, wherein a soundproof case is provided which covers the outer side of the fuel pump except for a portion close to the fuel pump. The soundproofing or sound absorbing material according to claim 1 or 2, wherein a soundproof case is provided to cover the outside of the fuel pump except for a portion adjacent to the fuel pump, and is provided on an inner surface side or an outer surface side of the soundproof case. Liquefied gas fuel supply apparatus characterized in that the soundproof layer consisting of. According to claim 1 or 2, wherein the soundproof case that covers the outside of the outside of the fuel pump, except for the portion close to the fuel tank is provided and the locking structure is provided with the soundproof case on the outer surface of the fuel tank A liquefied gas fuel supply device, characterized in that the fuel tank is detachably attached to the fuel tank. The soundproof case according to claim 1 or 2, wherein the soundproof case is provided so as to cover the outside of the fuel pump except for a portion close to the fuel tank, and the soundproof case includes the fuel tank on the outside of the fuel pump. The outer surface of the fuel pump side soundproof case which covers and accommodates the fuel supply pipe and the fuel return pipe except for the fuel supply pipe and the fuel return pipe connected between the fuel supply pipe and the fuel return pipe. A fuel tank side soundproof case and the fuel pump side soundproof case and the fuel tank side soundproof case are connected by an airtight connection pipe covering the fuel supply pipe and the fuel return pipe. Liquefied gas fuel supply unit.

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